Withajardins

Abstract

Withajardins A-D are new class of withanolides isolated from the leaves of Deprea orinocensis and characterized by having a bicyclic C-17 beta system and hydroxyl group at C-14 and C-17. The bicyclic system consists of a lactone and a homocyclic ring with six carbon atoms unlike the acnistins which have a five-membered homocyclic ring. The two classes of compounds were differentiated and their structures were identified by a series of HMQC, HMBC and finally X-ray diffraction experiments. Withajardins and acnistins would seem to evolve along quite dissimilar biosynthetic pathways although both types of compound show a marked immunosupressive effect on in vitro cultures of human lymphocytes.

What is claimed is: 
     
       1. A compound having the structure I: ##STR2## wherein: Y is O or a double bond; and R is OH, lower acyloxy, lower alkoxy or lower alkyl. 
     
     
       2. The compound of claim 1, wherein Y is O. 
     
     
       3. The compound of claim 1, wherein Y is a double bond. 
     
     
       4. The compound of claim 2, wherein R is OH. 
     
     
       5. The compound of claim 2, wherein R is acetoxy. 
     
     
       6. The compound of claim 3, wherein R is OH. 
     
     
       7. The compound of claim 3, wherein R is acetoxy. 
     
     
       8. The compound of claim 1, wherein R is methyl. 
     
     
       9. The compound of claim 1, wherein R is methoxy.